How to know defective EGR Valve Windstar 99 3.8

[raybaloy]

Kindly help me of how could I figure out if my EGR Valve is defective, since I do not have ODDII tools. Further, please let me know also about EGR valve regulator function. Thanks and regards.

[LeSabre97mint]

Originally Posted by raybaloy

Kindly help me of how could I figure out if my EGR Valve is defective, since I do not have ODDII tools. Further, please let me know also about EGR valve regulator function. Thanks and regards.

raybaloy

Why do you think your EGR valve is bad? Many autoparts stores will read codes for free for you. Check around. Were you able to read the posts on top of the Windstar page?

This link should help you learn about EGR: http://www.wisegeek.com/how-can-i-te...r-replaced.htm

Welcome to AFs!

Dan

[Andrew1941]

I am not sure if a 99 is the same as a 2001, so bare with me. On mine, I took off the vacuum line from the passenger side ventillation controls (under the hood look for the red 1/8" line passenger side near the A/C). This line, when the engine is running, has full vacuum. I then removed the green line, which comes from the EGR valve, from the solenoid on the back side of the manifold (passenger side) and with the engine running, hold the two lines together so there is no leak and vacuum is applied to the EGR valve. If the valve is functioning, you should be able to stall out the engine quite easily. If the valve diaphram has a leak or is stuck you may or may not be able to stall the engine.

If you want to test the DPFE sensor (which controls the EGR valve) then you need to perform the same test, but at the same time, test the voltage coming from the sensor (i.e. out of the sensor to the computer) and see what the voltage out (compared to ground) is before and during application of vacuum. Voltage out should vary as vacuum is applied, meaning that the pressure sensor is working. If the voltage doesn't vary, make sure you have a good connection and try again. If the voltage output stay the same, you have a bad DPFE sensor which is a common failure on Windstars. VERY EASY to change the sensor. If the sensor is a problem, what happens is DPFE tells the computer that the pressure drop in the EGR tube is not changing (meaning the flow is not increasing), even though it may actually be increasing. The computer then tells the EGR valve to open more, so it does, but the DPFE still sends back the same signal. Eventually the EGR valve is wide open and there is an incorrect mixture of exhaust gas to air combination in the engine. It can run rough and cause P0401 codes to appear. In my case, the engine was missing every once in a while, particularly on light accelleration on a gradual up hill condition. If I punched it, the missing would stop because the mixture in the engine would get better. Changin the sensor fixed it completely. Then if you remove the battery lead for a few minutes, the codes will go away OR get the codes reset with a code reader.